"They can have physical signs like being knocked out or not being able to remember the event. Could just be a behavioural change like irritability or later on they can have sleep disturbances like insomnia."

The AFL and the International Rugby Board have made the concussion guidelines available for download on their websites.

But Ms Haran says the message is not filtering down to childrens' sports.

"Sports organisations are trying hard to get the message out ... but there seems to be a problem in the translation of these guidelines to parents and children," she said.

"When the child has had the chance to go back to their club or their school ... to return to sport, still 74 per cent of them had not been told anything about what to do.

"We think it's quite significant that awareness of these guidelines needs to be improved."

Teenager had trouble remembering names 10 weeks later

Ms Haran says in one case, a 14-year-old girl had severe problems with her memory weeks after she was concussed.

"She fell backwards and hit her head while playing basketball," she said.

"After that, for 10 weeks, she's been having trouble remembering things like where her locker is at school or names of friends, things like that."

The girl's concussion was treated property and she was taken off the court straight away.

Ms Haran says concussion is a mild brain injury that can have serious consequences.

'[This was] a small knock," she said.

"Falling backwards, which happens commonly in sports, can cause such a big impairment in a child's life."

The study's results will be considered for publication next year.

The research is being presented for the first time at an emergency medicine conference in Adelaide this week.